A Jackcident is when a male human is masturbating over erotic material, but accidentally cums at the moment that the camera is looking at the male porn actors face or there is no one but the male porn actors in shot.

1. Jim was enjoying a good bishop bash, until he jackcidented all over the place

2. Bob: I had such a Jackcident last night!
James: You're a homosexual! Don't you deny it!
Bob: Seriously dude, it was a Jackcident!

The Urban Dictionary T-Shirt

An accident caused by one or more people jacking off at the sight of a nude person of their preferred gender walking down the street.

Person 1: How'd you total your car?
Person 2: There was this naked chick walking down the street. She was so hot, I just had to go for it
Person 1: Did you at least have a happy ending?
Person 2: Yeah, just before the jackcident.